body {
  font-family: Arial, sans-serif;
  background: #f5f7fa;
  margin: 0;
  padding: 20px;
}

.container {
  max-width: 500px;
  margin: auto;
  background: white;
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 0 10px #ccc;
}

h1 {
  text-align: center;
  margin-bottom: 20px;
}

label {
  display: block;
  margin-bottom: 5px;
}

input[type="number"] {
  width: 100%;
  padding: 10px;
  margin-bottom: 15px;
  font-size: 16px;
}

.categories {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.category h3 {
  margin-bottom: 5px;
}

canvas {
  margin-top: 30px;
}